Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thermoanaerobacter ethanolicus is a gram-positive thermophile that produces considerable amounts of ethanol from soluble sugars and polymeric substrates, including starch. Growth on maltose, a product of starch hydrolysis, was associated with the production of a prominent membrane-associated protein that had an apparent molecular weight of 43,800 and was not detected in cells grown on xylose or glucose. Filter-binding assays revealed that cell membranes bound maltose with high affinity. Metabolic labeling of T. ethanolicus maltose-grown cells with [(14)C]palmitic acid showed that this protein was posttranslationally acylated. A maltose-binding protein was purified by using an amylose resin affinity column, and the binding constant was 270 nM. Since maltase activity was found only in the cytosol of fractionated cells and unlabeled glucose did not compete with radiolabeled maltose for uptake in whole cells, it appeared that maltose was transported intact. In whole-cell transport assays, the affinity for maltose was approximately 40 nM. Maltotriose and alpha-trehalose competitively inhibited maltose uptake in transport assays, whereas glucose, cellobiose, and a range of disaccharides had little effect. Based on these results, it appears that T. ethanolicus possesses a high-affinity, ABC type transport system that is specific for maltose, maltotriose, and alpha-trehalose.
...
PMID:High-affinity maltose binding and transport by the thermophilic anaerobe Thermoanaerobacter ethanolicus 39E. 1069 63

The proteins encoded in the yicI and yihQ gene of Escherichia coli have similarities in the amino acid sequences to glycoside hydrolase family 31 enzymes, but they have not been detected as the active enzymes. The functions of the two proteins have been first clarified in this study. Recombinant YicI and YihQ produced in E. coli were purified and characterized. YicI has the activity of alpha-xylosidase. YicI existing as a hexamer shows optimal pH at 7.0 and is stable in the pH range of 4.7-10.1 with incubation for 24h at 4 degrees C and also is stable up to 47 degrees C with incubation for 15 min. The enzyme shows higher activity against alpha-xylosyl fluoride, isoprimeverose (6-O-alpha-xylopyranosyl-glucopyranose), and alpha-xyloside in xyloglucan oligosaccharides. The alpha-xylosidase catalyzes the transfer of alpha-xylosyl residue from alpha-xyloside to xylose, glucose, mannose, fructose, maltose, isomaltose, nigerose, kojibiose, sucrose, and trehalose. YihQ exhibits the hydrolysis activity against alpha-glucosyl fluoride, and so is an alpha-glucosidase, although the natural substrates, such as alpha-glucobioses, are scarcely hydrolyzed. alpha-Glucosidase has been found for the first time in E. coli.
...
PMID:Overexpression and characterization of two unknown proteins, YicI and YihQ, originated from Escherichia coli. 1529 95

Three analogs (5, 6, and 7) lacking polar substituents in the side chain of a naturally occurring alpha-glucosidase inhibitor, salacinol (1a), were synthesized by the coupling reaction of a thiosugar, 1,4-dideoxy-1,4-epithio-D-arabinitol (3), with cyclic sulfates (8, 9, and 10), and their alpha-glucosidase inhibitory activities were examined. All these simpler analogs (5, 6, and 7) showed less inhibitory activity compared to 1a, and proved the importance of cooperative role of the polar substituents for the alpha-glucosidase inhibitory activity. A practical synthetic route to 3 starting from D-xylose is also described.
...
PMID:Synthesis and biological evaluation of deoxy salacinols, the role of polar substituents in the side chain on the alpha-glucosidase inhibitory activity. 1619 77

Four chain extended homologues of salacinol, a naturally occurring glycosidase inhibitor, were prepared for evaluation as inhibitors of glucosidase enzymes involved in the breakdown of carbohydrates. The syntheses involved the reactions of 1,4-anhydro-2,3,5-tri-O-benzyl-4-thio-D-arabinitol with cyclic sulfate derivatives of different monosaccharides. Debenzylation of the products afforded the novel sulfonium sulfate derivatives of D-glucose, D-galactose, D-arabinose, and D-xylose that are of interest in their own right as glycosidase inhibitors. Reduction to the corresponding alditols then afforded the homologues of salacinol containing polyhydroxylated, acyclic chains of 5- and 6-carbons, differing in stereochemistry at the stereogenic centers. Three of the chain-extended homologues inhibited recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with Ki values in the low micromolar range, of approximately the same magnitude as salacinol, thus providing lead candidates for the treatment of Type 2 diabetes.
...
PMID:Synthesis of sulfonium sulfate analogues of disaccharides and their conversion to chain-extended homologues of salacinol: new glycosidase inhibitors. 1643 29

Phytohemagglutinin, the glycoprotein lectin of the common bean, Phaseolus vulgaris, has both high-mannose (Man(8-9)GlcNAc(2)) and modified oligosaccharide side chains. The modified side chains have glucosamine, mannose, fucose, and xylose in the molar ratios 2:3.8:0.6:0.5, and are resistant to hydrolysis by endoglycosidase H. Synthesis and processing of side chains in the presence of 1-deoxynojirimycin, an inhibitor of alpha-glucosidase, results in the formation of chains which are all alike. They are sensitive to endoglycosidase H, do not contain fucose, and are largely resistant to alpha-mannosidase. This indicates that they are probably high-mannose chains blocked by terminal glucose residues. Synthesis and processing of side chains in the presence of swainsonine, an inhibitor of alpha-mannosidase II, results in the formation of normal high-mannose chains, and of modified chains which contain fucose residues, are resistant to endoglycosidase H, and can be distinguished from normal modified chains only by the presence of extra mannose residues.Processing of the phytohemagglutinin modified chains of PHA under normal conditions involves the attachment of peripheral N-acetylglucosamine residues in the Golgi complex and their subsequent removal in the protein bodies. The attachment of the N-acetylglucosamine residues is largely inhibited by deoxynojirimycin but still occurs in the presence of swainsonine. The results presented in this work show that processing of the asparagine-linked oligosaccharides is under the control of several glycosidases and glycosyltransferases and involves the formation of intermediate products.
...
PMID:Abnormal processing of the modified oligosaccharide side chains of phytohemagglutinin in the presence of swainsonine and deoxynojirimycin. 1666 12

A novel species of the Pasteurellaceae, Avibacterium endocarditidis sp. nov., is proposed based upon characterization of 27 isolates from valvular endocarditis in adult broiler parents. All isolates shared the same PFGE type after digestion of DNA with SmaI and XbaI. In addition, all isolates meet the phenotypic characters for the genus Avibacterium. Separation of the novel species from other species of Avibacterium was possible by means of tests for catalase, symbiotic growth, aerobic growth on agar, acid production from glycerol, xylitol, (+)-L-arabinose, (-)-D-mannitol, (-)-D-sorbitol, (-)-L-fucose, (+)-D-galactose, maltose, trehalose, raffinose and dextrin in addition to reactions with ONPG (beta-galactosidase) and PNPG (alpha-glucosidase). The closest relationship was observed with Avibacterium gallinarum which, however, can be separated from Avibacterium endocarditidis in acid production from (-)-D-mannitol, (-)-D-sorbitol and (-)-L-fucose. The highest 16S rRNA gene sequence similarity (98.4 %) was found to strain Modesto, belonging to serogroup C of Avibacterium paragallinarum. recN gene DNA sequence similarities corrected by the formula of Zeigler (2003) (Int J Syst Evol Microbiol 53, 1893-1900) documented 85 % or less DNA sequence similarity between the type strain of Avibacterium endocarditidis and species of Avibacterium, confirming the separate species status of this taxon according to the multilocus sequence analysis method of Kuhnert & Korczak (2006) (Microbiology 152, 2537-2548). The type strain of Avibacterium endocarditidis sp. nov., strain 20186H4H1(T) (=CCUG 52860(T) =DSM 18224(T)), was isolated from valvular endocarditis of a chicken in Denmark in 2004.
...
PMID:Avibacterium endocarditidis sp. nov., isolated from valvular endocarditis in chickens. 1768 46

A Gram-positive, short diphtheroid-shaped organism was isolated from a sow's placenta of an abortion. This novel isolate, strain Murakami(T), was examined physiologically, chemotaxonomically and phylogenetically. Cells had an irregular V-shaped or palisade arrangement. Colonies appeared translucent on TMVL agar. Cells were strictly anaerobic, negative for catalase and gelatin decomposition and positive for nitrate reduction and soluble starch hydrolysis. Fourteen sugars including glucose were utilized as carbon sources for growth, but 15 sugars including arabinose were not. alpha-Galactosidase, beta-galactosidase, alpha-glucosidase and leucine arylamidase were produced, but beta-glucosidase was not. Fermentation products were lactic, succinic and acetic acids. Sugars of whole cells consisted of rhamnose and ribose. The amino-acid composition of the peptidoglycan was glutamic acid, alanine and lysine in the molar ratio of 1 : 2 : 1. The main fatty acid components of whole cells were C(14 : 0), C(16 : 0), C(16 : 1)omega7 and C(18 : 1)omega9. The bacterial menaquinone was MK-10(H(4)). The polar lipids were phosphatidylethanolamine and two unknown phosphatidylinositol mannosides. The G+C content of the genomic DNA of strain Murakami(T) was 63.8 mol%. Phylogenetic analysis of 16S rRNA gene sequences from strain Murakami(T) and other members of the genus Arcanobacterium supported the phenotypic findings that strain Murakami(T) represents a novel species, for which the name Arcanobacterium abortisuis sp. nov. is proposed. The type strain is Murakami(T) (=ATCC BAA-1522(T) =DSM 19515(T) =JCM 14813(T)).
...
PMID:Arcanobacterium abortisuis sp. nov., isolated from a placenta of a sow following an abortion. 1950 37

Two luminous marine bacterial strains, LC2-005(T) and LC2-102, were isolated from seawater at Kuroshio Region and Sagami Bay in Japan, respectively. These bacteria were Gram-negative, oxidase-positive, catalase-positive, motile and rod-shaped. On the basis of 16S rRNA gene sequence analysis, strains LC2-005(T) and LC2-102 formed a cluster within the Vibrio harveyi species group. However, multilocus sequence analysis using five loci (pyrH, ftsZ, mreB, gyrB and gapA) and DNA-DNA hybridization experiments indicated that these strains were distinct from the currently known Vibrio species. Additionally, these strains differ from related Vibrio species in utilization of glucose, mannitol, inositol, sorbitol, rhamnose, sucrose, melibiose and arabinose, production of lysine decarboxylase, ornithine decarboxylase, tryptophan deaminase, esterase (C4), lipase (C4), chymotrypsin, acid phosphatase, alpha-glucosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase and the ability to reduce nitrate to nitrite. The major fatty acids were C(15 : 0) iso 2-OH and/or C(16 : 1)omega7c, C(16 : 0), C(18 : 1)omega7c and C(14 : 0). The DNA G+C contents of strains LC2-005(T) and LC2-102 were 45.2 and 45.5 mol%, respectively. On the basis of the polyphasic taxonomic evidence presented in this study, it can be concluded that strains LC2-005(T) and LC2-102 belong to the same genospecies and represent a novel species of the genus Vibrio, for which the name Vibrio azureus sp. nov. is proposed. The type strain is LC2-005(T) (=NBRC 104587(T) =KCTC 22352(T)).
...
PMID:Vibrio azureus sp. nov., a luminous marine bacterium isolated from seawater. 1954 36

A collection of 12 strains, isolated from diseased tortoises and tentatively identified as [Pasteurella] testudinis-like based on phenotypic characters, was compared with three reference strains of [P.] testudinis. All strains could be separated from the reference strains with respect to 16S rRNA gene sequences, partial sequences of the rpoB housekeeping gene and by phenotypic characters. Based upon differences in 16S rRNA and rpoB gene sequences, the new isolates are suggested to represent a novel species in a new genus of the family Pasteurellaceae Pohl 1981, for which the name Chelonobacter oris gen. nov., sp. nov. is proposed. The type strain is 1662(T) (=CCUG 55632(T)=DSM 21392(T)). beta-Haemolysis and acid production from (+)-l-arabinose, dulcitol, (-)-d-mannitol, (+)-d-mannose, trehalose and salicin separated the new strains from members of existing genera of the family Pasteurellaceae, in addition to the beta-galactosidase, urease and alpha-glucosidase reactions. Differences in indole production, phosphatase, beta-glucosidase and production of acid from dulcitol and trehalose separated C. oris from [P.] testudinis. Several phenotypic characters separated C. oris from Bisgaard's taxa 14 and 32.
...
PMID:Comparative studies on [Pasteurella] testudinis and [P.] testudinis-like bacteria and proposal of Chelonobacter oris gen. nov., sp. nov. as a new member of the family Pasteurellaceae. 1957 48

A class of drugs in use for treating type II diabetes mellitus (T2D), typified by the pseudotetrasaccharide acarbose, act by inhibiting the alpha-glucosidase activity present in pancreatic secretions and in the brush border of the small intestine. Herein, we report the synthesis of a series of 4-substituted 1,2,3-triazoles conjugated with sugars, including D-xylose, D-galactose, D-allose, and D-ribose. Compounds were screened for alpha-glucosidase inhibitory activity using yeast maltase (MAL12) as a model enzyme. Methyl-2,3-O-isopropylidene-beta-D-ribofuranosides, such as the 4-(1-cyclohexenyl)-1,2,3-triazole derivative, were among the most active compounds, showing up to 25-fold higher inhibitory potency than the complex oligosaccharide acarbose. Docking studies on a MAL12 homology model disclosed a binding mode consistent with a transition-state-mimicking mechanism. Finally, the actual pharmacological potential of this triazole series was demonstrated by the reduction of postprandial blood glucose levels in normal rats. These compounds could represent new chemical scaffolds for developing novel drugs against T2D.
...
PMID:Synthesis, biological activity, and molecular modeling studies of 1H-1,2,3-triazole derivatives of carbohydrates as alpha-glucosidases inhibitors. 2017 Jan 90


<< Previous 1 2 3 4 Next >>

---